Robust two-dimensional bipolar magnetic semiconductors by defect engineering

Bipolar magnetic semiconductors (BMS) are promising for applications in spintronic devices and quantum computers as 100% spin polarized currents with reversible spin direction can be easily controlled by a gate voltage in such materials. Herein, we perform first-principles calculations to investigate the structural and electronic properties of intrinsic defects in monolayer half-semiconductor CrSiTe3. Our calculations show that Cr-Si or Si-Cr antisite defects which are thermodynamically dominating in CrSiTe3 can trigger the bipolar magnetic property in CrSiTe3. These BMS characters are robust and survive under a large applied external biaxial tensile strain and electric field. Our results demonstrate a new path to design BMS materials by defect engineering, promoting the applications of two-dimensional magnetic materials in spintronics.